function changeCSS(cssFile){
	cssFile = "css/" + cssFile + ".css";

	var oldlink = document.getElementsByTagName("link").item(0);
    var newlink = document.createElement("link");

    newlink.setAttribute("rel", "stylesheet");
    newlink.setAttribute("type", "text/css");
    newlink.setAttribute("href", cssFile);

    document.getElementsByTagName("head").item(0).replaceChild(newlink, oldlink);
}

function changeFunc() {
    var selectBox = document.getElementById("selectCSS");
     var selectedValue = selectBox.options[selectBox.selectedIndex].value;
    changeCSS(getTheme());
   }

function getTheme(){
	var selectBox = document.getElementById("selectCSS");
    var selectedValue = selectBox.options[selectBox.selectedIndex].value;

    return selectedValue;
}